According to the state of art, such valve types are widely used in many countries situated in zones of increased seismic activity hosting intensive gas utilization. While the system most commonly used is the ball system.
An example of a ball system can be given as follows: due to the seismic movement, a ball falls into the gas passage effectively shutting off the gas flow. Such systems exhibit variations with respect to the ball diameter and weight and also to their way of use. However, in said systems, when the gas pipe gets damaged during an earthquake, said ball, even if it has blocked the gas passage, may come out of its housing and lead to gas leakage. This is the biggest and most significant problem of the ball systems.
Another system type includes those systems wherein the ball is located at a certain position as in the above example, said ball leaves its housing under the influence of the seismic movement to activate the system and as a result the gas flow is stopped.
Another type of device with mechanical sensor, which is currently in use, is the flap valve. Here the ball releases a tab, to which the flap is attached, from said flap and closes the flap by means of the spring force. In this system, assembly is performed horizontally.
Another known method involves the valves with magnetic flap retainer. These operate on the principle that the magnetic piece, which keeps the flap open, releases said flap as a result of the seismic movement and the flap stops the gas flow.
Other than those described above, there are electro-mechanical seismic gas stopper devices available in the market. It is a necessity for such devices to operate with a solenoid valve. The devices send a signal generated during an earthquake to the solenoid valve, and the solenoid enables the valve to be closed by means of a coil windings-bobbin. Battery feed is also necessary in this device type. These devices to become unable to serve their function when the battery is empty or when the electronic board fails. To enable their continued function, they must be subjected to periodical yearly maintenance. In addition, the cable connection between the electromechanical earthquake sensor and the solenoid valve is also a risk factor in said system. The effect of the ball in case of earthquake and the structure of the mechanism that blocks the gas is passage show differences from one another. In our country, the ball systems and the electronic seismic sensor devices are also used along with a solenoid valve in order to send the current to the electronic circuit during an earthquake.
In case said ball systems are used, the assembly should be done very carefully. In particular, a very precise approach is needed during balancing, because, in case the balancing is not given due attention, the system performs an early shutdown, thus having to close the valve unnecessarily. In this case, in order to restart the gas flow, the authorized personnel from the gas supply center should is to be called. This leads to increased work load for the gas distribution companies and to an unnecessary labor waste.
The present invention is the mechanical earthquake valve with orifice closure, comprising at least one valve and sensor mechanism, aimed to resolve the technical problems in the state of the art.